Prefabricated wall and roof panels having an inner and outer skin coupled to a center core are known in the art. The center core may be of styrofoam or of various plastic materials well-known in the art. In addition to styrofoam, polyisocyanate or polyurethane foam has been used as a core between inner and outer skins such as corrugated metal panels, blandix, wallboard, etc. The difficulty with using polyurethane and/or polyisocyanate or other similar type plastic materials, is that upon combustion they give off toxic gasses, which may be fatal to the occupants of the building. When the inner and outer skins are coupled directly to the center core by means of mechanical fastners, there will be a loss of "R" value through the wall since there is a heat transfer through the wall depending on the relative temperatures of the inside and outside of the building. This heat transfer increases the amount of energy needed to either heat or cool the building. If the inner and outer skins are glued to the center core, as it is done in some cases, it becomes expensive because of the amount of labor that is required to form the panel. The building industry is very competitive, especially when it comes to prefabricated wall panels. Therefore, there is a need in the construction industry for a prefabricated wall and/or roof panel that is inexpensive, easy to assemble and install and will not give off toxic fumes in case of a fire and will retain a high "R" value reducing the energy costs to either heat or cool the building.
My invention incorporates a center core having an inner and outer skin of corrugated metal coupled thereto by means of a "C" shaped pultrusion; said pultrusion separating the skins from the center core thereby forming an air envelope between the core and each of the outer and inner skin.
In my preferred embodiment, I use a styrofoam or a non-combustible mineral wool insulation as a center core panel approximately three feet by four feet. A combination of styrofoam and a non-combustible mineral wool insulation may also be used as the center core. A pultrusion in the form of a "C" channel comprising in part materials covered under my U.S. Pat. Nos. 3,920,603, 4,028,134, 4,027,401 and 4,216,136 in combination with fiberglass material, is positioned on the three foot end of the styrofoam center core panel. The pultrusion is formed by methods well-known in the fiberglass industry. A pair of corrugated metal skins are positioned against the "C" channel pultrusion and are coupled thereto by means of screws that run from the skin to the "C" channel and then into the styrofoam center core panel. The skin does not make direct contact with the styrofoam center core panel, but in fact, forms an envelope of air between it and the center core. The envelopes of air on each side between the center core and the skin, temper the air movement which does not occur when the skin is flat against the center core as in the case when the skins are glued directly to the center core. In addition, the double air envelope created by the pultrusion, forms a vapor barrier on each side of the center core, which inhibits moisture from forming on the skins in winter as well as summer. In addition, the pultrusion inhibits the transfer of heat and/or cold between the skins because of the dual air envelopes.
The "C" channel pultrusion creates a thermal break and provides an excellent means for fastening the inner and outer skins to the pultrusion. The pultrusion does not promote fungus nor will it rot as it would if made of wood, nor give off toxic gasses in combustion if made from a plastic material.
In the event of a fire, the "C" channel compartmentalizes the combustion of the center core and confines it between "C" channels thereby localizing it and preventing it from extending to the entire wall. The combustion is contained between the inner and outer skins between the "C" channel pultrusions. In essence, in may preferred embodiment, the pultrusion acts as a firewall every four feet.